Spraying device



July 5, 1960 Original Filed June 7. 1955 J. G. YAHNKE 2,943,795

SPRAYING DEVICE 2 Sheets-Sheet 1 -llllllll-IIHIIB `Hiliilllllllml Invezfor James G. Yahrzke, dec'd,

July 5, 1960 J. G. YAHNKE 2,943,795

SPRAYING DEVICE Original Filed June 7, 1955 2 Sheets-Sheet 2 |06 loo n [o6 'o4 Fig. 5 FaoM PRESS CONTROL SouRcE ,f SWITCH s' fu y 76 I8 f Inventor' James' G.Yahnke, decd.

' {Him-neg( yUnited States Original application June 7, 1955, Ser. No. 513,680, now Patent No. 2,817,600, dated Dec. 24, 1957. Divided and this application Aug. 16, 1957, Ser. No. 678,658

' 1 claim. (ci. 239-128) This invention relates to a spray device and more particularly to a device 4for spraying liquids in response to an intermittent "signal The `inventionalso relates to a novel spray method. 1

. .In the printing art it has been a practice for s ome time to` coat aprinted sheet with wax to protect the printing on the sheetfrom becoming damaged by. 'abrasive .contact with'pther sheets.` Thepreviouslyknown devices never provecompletely satisfactory, however, because of in.

' n't operation.' s therefore `a principal vobject of this invention to proliquid spray device fcliaracterizedby etiicient jand terial;

` Ipo sitive operation forpreventingoifsetjin printed ma- Anothen objectof' the invention is to provide a liquid -i spray dev ice characterized by remotely controlled intermitte'nt operation."` D A further 'objectofthe invention Yis"V to providean improved method of spraying. a liquid by a Siphon pn'n- Qp1e'...-.. Y.

Still -anotherfobject of the .invention is `to provide an improved methodl of preventing offset in printing by spraying wax onto a printed material;V

A still further object Tof the `invention is to provide an improvedjspray head operating on the siphon principle and characterized by fast and substantially dripless cut-olf. In "the accomplishment jof the foregoing objects fand in 'accordance with'fthepractice of this invention there is nowi provided a` device l 'for spraying hot'V liquids which Figure 5 is an electrical wiring diagram showing the control features of the invention.

yConsidering the drawings in greater detail the device illustrated in Figs. 1 and 2 consists of a heating and supply tank 10 which is heated by the electrical element 12 or other suitable, readily controllable source of heat. The tank is contained within a shell 16 which in turn is mounted on the support member 14 above the hollow supply bar 18. A thermostatic control 20 is positioned within the tank 10 and -is connected to the heating element 12 to maintain the contents of the tank at a predetermined temperature. A oat 22 is provided within said tank and is connected by a rod 24 to a signal element 26. A switch28 is adapted to be closed by a linger 30 attached to the rod 24 and to energize an indicating light 32 mounted on the shell 16 or at any suitable remote location.

I'he space between the tank 10 and the shell 16 is used for heating the compressed air supply to the sprayers. As illustrated in Fig. 2 one may employ a spirally wound tube 34 through which the air passes after having been admitted by the valve 36 from the source (not shown). It lwillV be apparentthatthe space may be sealed except for an inlet -andf'outlet for air andthe tube or coil 34 may be eliminated.` In such case the circulating air will pick upheat: from the sides oi' the hot tank i0 and` `from the element-1 2.A `Suitable inletand outletv openings could corres ond lto theopenings '38'.andjtijin the shell 16 whiclrreceivefthe tubing-34, v A

, eh-ot (or heated air).`1eaves the heated space and passes, through thefpipe 42'- to the solenoidbperate'd comprises afhe'ate'd :supplytank for said liquid, an elongatedhe a ted containelQl hQt liquid positioned adjacent an'bbjefct'lto v be spraye` k l, means4 connecting said tank said` oontainer, Ysiphonjspray' means mounted eidjacent. said* container '.andj .adapted to `v withdrawliquid therefrom in responseto thev passagefof. compressed air through said means, and means for starting and stopping ilow of'.said.compressed air, -preferablyby remote i c ntrol actuatfedyby 'the passage offan object to be sprayed:

` past a reference point. 3 'The means connecting the tank with the container is preferably adapted to maintain a'constant level of liquid lis prepared in thetank 10 `and passes through the'pipeV 50 Yand'themanually operated valve 52 tothe solenoid opertlie container, asbyfa float controlled valve.` ontainerjis open to the atmosphere and may have one orafplnrality ofsiphon spray heads extending therein and' being-:supplied therefrom.

' IThese and other-objects andi advantages of theinvention will 'become apparentupon a reading'of the following- 'detaileddescription of the invention taken in conjunction with the accompanying drawings inwhich: l .Figu'reglis `anelevationalview of one embodiment of a spray device according to Vthe invention; v i

Figure 2 is an enlarged view partly in vertical section and-'partly in elevation of the supply and control elements f a device according to the invention; Y

Figure 3 is*` an yenlarged sectional view taken along the lines '3 of Fig. 2;

y A@Figure""4;is Ya cross-sectional view through one embodiment of a spray head according to the invention, and' ation of an electricalf switch (not shown) by vthe Vpassage v of av sheetof material to be printed past a determined location. YFor instance -a sheet ofpaper or cardboard 46 (Fig. 1)'carried'on a web or conveyor 4S can be used to trip va biased lever (not shown) and actuate the switch, signalling through-thesolenoid to the valve 44 and opening Isaid valve to-pass air to the sprayers. When the sheet dhaspassed the reference point the lever returns to initial'-V position, shutting ofic the supply of air `to the sprayers as'will be explainedin more detail later. As another embodiment of the idea one may employ'an electronic eyeA and beam'of light which is interrupted by thepassage of a sheetthrough the beam, and the inter-A ruption being used by conventional methods to actuate the solenoid valve 44.

i A supply of heated liquid such as molten paraffin wax on the surface of the liquid 6tiin`the supply bar 18 andas the liquid is used up the oat opens the valve 56^and allows'more liquid to enter from the tank 10. In preferred practice thebar 13 is substantially'square andis maintained about half-full of liquid during operation. In one embodiment the bar 13 is about 2 inches square and about 1 inch of molten paraffin is maintained dur'ingfoperation. An opening 62 is pro-v Y videdin one end of said bar 18' to admit the oat 58 and the discharge valve 56, and to vent the bar sothat the sprayers may function properly. The bar is supported as at 63.

Strip heating elements 64 and 66 are attached to aV side of the bar 18, preferably to the side opposite the spray` nozzles Valthough other vlocations -rnaybe suitable also. connected -in parallel with the-heater `12 of lthe taule-1) so..that the bar 18 will operate at substantially the same temperature as the tank. The other of theelements, usually the upper, 66 is connected to a timingdevice and is used principally as a heating-up or preheating aid. For example, the timer may be set to turn on the element 66 about 30 minutes before the press and spray unit are expected to be in operation.

Coming now to the spraying element' itself there is illustrated in Figs. Vl, 2 and 3, a spray head 68 (or several of them) which is mounted on the bar 18,v and a conduit`70 extendsV from said head to a point beneath the surface of the liquid 60. The head 68 has service lines 72 "for liquid and 74 for compressed air, and the latter is connected to a service main 76 which communicates with the air solenoid valve 44.

Fig. 4 shows the structure of the spray head 68 inl cross-sectional detail. Compressed air is conveyed to the head 68 through the -line 74 `and passes through a conduit 78 in the upper portion 80 of the head. The conduit 78 communicates with a chamber 82 formed between the lower ring 84 of the head and the upper portion 80. A small hole 86 is provided in'the inner element 88 (or a plurality of Aholes may be provided if desired) and connects the chamber 82 with aninner air chamber 98. Compressed air leaves the chamber A90 by the small Vcircular opening 92 in the element 8&8.

Molten wax or other hot liquid is sucked up through the conduit 70 from Ythe liquid supply in the bar--18 (Fig.

3). Said wax passes through the pipe'72 to the spray.

104. Air escapes from said element through a singleV angled opening 106 in each and the stream of air sof emitted passes through the cone of air and Wax issuing One of the elements, usually thelower, 64 is.

1.` so that one or any'desired numberof'spray-'heads can be operated at will.

As compressed air passes through the spray head 68/'it creates a vacuum on the wax discharge nozzle 100 and draws Wax from the supply in the bar 18 to the nozzle. Here the wax is atomized into tiny globules which solidify in the air before striking: thefslieet of paper 46. The tiny wax pellets adhere to the printed-sheet and successfully prevent offset of the partially dried printing ink and sticking of the Ysheets to one another; pellets provide a desirablefe'el and'gloss'to theasheet and cause the sheets to slide over one another 4with ease.

When molten'wax -isgwithd-rawn: from the bar- 18 the supply will be continually replenished bythe-action of the oat activated 'valve 56-'which allowswax Y to drain from the tank 10., When the supply in the tank becomes low the float gaugeturnson the indicator light and warns the operator to put more wax in the tank.

When the end of the printed. sheet which may,of course, be quite smallV or may range insize up to a large roll of paper or the'like, passes the predeterminedreference point the lever (biased) or theelectricfbeam will energize the solenoid valve 44 to close andl stop the ow of compressed Vair tothe spray heads. The heads will. stop spraying instantaneously thereby providing one of the significant ladvantages of this apparatus. Thatis,

the spray is stopped instantaneously withnooversprvayn ing beyond the paper sheet and no dripping.v Tlsoof curs becausethe Vwax isV beingdrawn up to the spray from the center of the head and spreads said cone to a Y wide but rather thin spray'pattern. In Fig. 3 for instance the spray pattern 108 is shown depositing wax on the paper 46 being carried through said pattern by the conveyor 48.

In the preferred operation of the vdevice one charges the material to be heated, such as parain wait, into the tank 10.' Wax is putinto the tank 10 in the form of; flakes, blocks or chips. element 12 to melt the wax and current is simultaneously applied to the heating element 64 on the bar18 `to pre# heatthe bar 64 and the spray nozzleassembly.V If the device is being put back into operationV after setting overnight with wax in it7 the timer (Fig. 5) may be preset -to supply current to the preheat element '66 on the bar 18. f

' When the wax inthe systemV is molten and at proper operating temperature (between`aboutll0 Rand 400 F.) the press is started and printing of sheets is begun. When the first sheet passes a predetermined reference point it lactuates a lever or cuts a beam of light thereby energizing a switch 11i) (see Fig. 5)' which closes the circuit and energizes the solenoid air valve 44 to admit compressed air from the source to the air systemof the device. Compressed air passes through .the -pipe 76 to the individual spray head 68 which,incidentally,` can be closed oi by means?. of the valves 112'(Eigslfl and. 2)

Current is applied to the heatingY nozzle 100 by vacuum and [theinstantV the vvacuum isv broken the weight of the column of wax -in the pipetends to pull the'wax back'frorn'the nozzle into the bari As-previously indicated the molten waxv issuing from the nozzle solidifies quickly in the air Vand strikes the sheet in the form of tiny globules, adhering Ito the sheet in a thin layer. While the device yillustrated in the accompanying drawings is showny operating overthe paper sheet it will be apparent that the device may-be soV mounted that the spray heads spray' thewax onto the bottom of a sheet passingfover them, or onto a sheetl passing alongsideor in front of the device.

The amount-of wax deposited on the sheet can be varied at will simplyvby increasing or decreasing theY airA pressure on the system. Increasing-the lair pressure causes a greater volume of air to pass throughthenoz'zley thereby drawing or siphoning a larger amountof Decreasing the air pressure of course has -the .opposite elect. Y 'l While the device has lbeen specifically describ'edfasv a wax spray apparatus it is intended thatthe ldevice may be Vusedrfor anyother suitable purpose. Liquids, emulfv sions,'fsus'pensions and dispersions, both hot and cool, vr'nay be sprayed by the device. For example, wax emulsions, paints, lacquers, varnishes, hot and coldwater and 'the like may -be applied -by this rnethodfand"apparatus,y which has special, but Vnot exclusive, application to the printing arts. y Y Y Y Among the materials Vwhich can be sprayed 'ac'cording to this invention are paper, cardboard, carton stock,

Y plastic sheeting, pressed hardboard 'and like-materials'.

.- It will be `apparent lfrom the foregoing V.description of the invention that there is now'provided-.a rtype of'wax terials such as the molten vegetable waxes (carnauba) compatible with printing inks vand can be printed over quite well.

This application Vis a division of co-pending application Serial No. 513,680 led June 7, 1955, now Patent No. 2,817,600'.

Having described the invention, what is claimed as new is:

A device for spraying hot liquid comprising a supply tank for said liquid, a heating element attached to said tank, an elongated container for hot liquid, a heater atvtached to said container, conduit means connecting said tank with said container, siphon spray means comprising concentric conduits the inner of which is connected with said container and adapted to withdraw liquid therefrom in response-to the passage of compressed air through the outer of said conduits, and a supply of air 10 under pressure connected to said outer conduit.

References Cited in the le of this patent UNITED STATES PATENTS 15 1,047,619 Decker Dec. 17, 1912 1,751,343 Mock Mar. 18, 1930 2,146,808 Flint Feb. 14, 1939 2,506,412 Chausse May 2, 1950 2,559,407 Dalry-mple July 3, 1951 

